Kelley — 96 — Mycotrophy 



from whence it comes in contact with the soil. Goebel (1887) stated 

 that the lower, non-meristematic, portion of the prothallus of L. 

 inundatum was always without exception inhabited by a fungus 

 which forms coils within the cell content without killing the cell, the 

 nucleus remaining plainly visible. From the coil a branch may go 

 through to the next cell. The fungus is limited to one or two cell 

 layers forming a zone separated from the exterior by several cell 

 layers, and it is unable to penetrate the meristem, or lobes of the 

 prothallus. The infected cells do not contain starch but drops of oil. 



According to Holloway (1920), a fungal symbiont occurs in 

 epiphytic prothalli of the New Zealand Lycopodium Billardieri, L. B. 



Fig. 6. — Portion of mycothallus of Lycopodium obsciirum 

 shown in section, with pelotons or fungal coils and oil 

 globules (Redrazvn from F. L. Barrows, in Contr. Boyce 

 Thompson Inst. 7:299, fig. 34, 1935). 



gracile, L. varium, and in the epigeic species L. cernuum, L. laterale 

 and L. ramidosum. In the epiphytic species, the fungus occupies the 

 base of the prothallus even in epidermal cells at the prothallial point, 

 and grows forward with the prothallus, occupying a zone between the 

 epidermis and the central conducting cells. Fungal coils soon disap- 

 pear in many of the cells, their place being taken by clusters of darkly 

 staining oval "spores" which are probably used by the prothalli ; but 

 oil droplets were not seen. In the epigeic species, fungus is present 

 only in the epidermis of prothallus but occurs in inner tissues of pro- 

 tocorm where only "spores" were observed. 



